Introduction of the steel products, such as slabs, into reheating or treatment furnaces is generally ensured by means adapted to push the products inside the furnace from a roller gear bed on which these products are conveyed. The products are most often pushed on slide rails which are disposed between the rollers.
However, during their thrust, the lower face of the steel products rubs on the approach rollers and on the rails, which marks this lower face. Furthermore, the thrust effort is considerable and requires high-power mechanical drive equipment.
U.S. Pat. No. 2,360,661 describes a device for charging slabs or other steel products into a reheating or treatment furnace, which comprises an approach roller gear bed extending along the charging opening of the furnace, means for pushing the products inside the furnace from the roller gear bed, and arms which extend between the approach rollers, themselves bear rollers with axes parallel to the charging opening, and are articulated with respect to the structure of the furnace, outside said furnace.
The arms are retracted when a slab arrives on the approach rollers in front of the charging opening. The arms are then raised so that the slab is supported by the rollers of these arms, which enables it to be pushed without friction towards the position required by the conveyor of the furnace.
However, the presence of the articulation outside the furnace involves a considerable overhang, which renders operation delicate due to the weight of the slabs.